Details of a Researcher - KATAYAMA Ikufumi

Papers - KATAYAMA Ikufumi

about 123

Ultrafast on-demand exciton formation in a single-molecule junction by tailored terahertz pulses

Kensuke Kimura, Ryo Tamaki, Minhui Lee, Xingmei Ouyang, Satoshi Kusaba, Rafael B. Jaculbia, Yoichi … Show more authors

Science 387 ( 6738 ) 1077 - 1082 2025.3 [Reviewed]

DOI

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal) Joint Work

Three-dimensional bonding anisotropy of bulk hexagonal metal titanium demonstrated by high harmonic generation

Katayama, I; Uchida, K; Takashina, K; Kishioka, A; Kaiho, M; Kusaba, S; Tamaki, R; Shudo, K; Kitaji … Show more authors

COMMUNICATIONS PHYSICS 7 ( 1 ) 2024.12 [Reviewed]

DOI Web of Science

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Joint Work

Terahertz sum-frequency excitation of coherent optical phonons in the two-dimensional semiconductor WSe2

Satoshi Kusaba ORCID logo ; Haw-Wei Lin ORCID logo ; Ryo Tamaki; Ikufumi Katayama ORCID logo … Show more authors

APPLIED PHYSICS LETTERS 124 ( 12 ) 2024.3 [Reviewed]

DOI Web of Science

Language：English Publishing type：Research paper (scientific journal) Single Work

Thermally-induced nanoscale phase change in chalcogenide glass Cr2Ge2Te6 revealed by scanning tunneling microscopy

63 ( 1 ) 015504 2024.1

DOI Web of Science CiNii Research

Language：English Publishing type：Research paper (scientific journal) Joint Work

Single-shot terahertz waveform detection of resonant tunneling diode in time-domain

Tamaki, R; Takahashi, K; Arikawa, T; Katayama, I

2024 49TH INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER, AND TERAHERTZ WAVES, IRMMW-THZ 2024 2024

DOI Web of Science

Language：Japanese Publishing type：Research paper (scientific journal) Joint Work

Single-molecule electroluminescence induced by THz-field-driven electron tunneling

Kimura, K; Tamaki, R; Imada, H; Katayama, I; Takeda, J; Kim, Y

2024 49TH INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER, AND TERAHERTZ WAVES, IRMMW-THZ 2024 2024

DOI Web of Science

Language：Japanese Publishing type：Research paper (scientific journal) Joint Work

Observation of interplay between phonon chirality and electronic band topology

Hernandez, FGG; Baydin, A; Chaudhary, S; Tay, F; Katayama, I; Takeda, J; Nojiri, H; Okazaki, AK; Ra … Show more authors

SCIENCE ADVANCES 9 ( 50 ) 2023.12 [Reviewed]

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Language：English Publishing type：Research paper (scientific journal) Joint Work

Ultrafast pump-probe spectroscopy via chirped-pulse up-conversion with dispersion compensation

Tamaki, R; Suzuki, M; Kusaba, S; Takeda, J; Katayama, I

OPTICS EXPRESS 31 ( 24 ) 40142 - 40150 2023.11 [Reviewed]

DOI Web of Science PubMed CiNii Research

Language：English Publishing type：Research paper (scientific journal) Publisher：Optica Joint Work

In this study, ultrafast transient signals were detected on a single-shot basis using chirped-pulse up-conversion spectroscopy with dispersion compensation. Unlike in the conventional time-encoding technique using chirped pulses, distortion of the ultrafast waveform was reduced by applying dispersion compensation to the chirped probe pulses and using sum-frequency generation with the chirped readout pulses. The method was applied to terahertz time-domain spectroscopy and near-infrared pump–probe spectroscopy, providing ultrafast observations with an improved temporal resolution comparable to the transform-limited pulse durations. Terahertz waveforms, Kerr rotation signals, and phonon-polariton oscillations were measured accurately with no significant waveform distortion, thereby showing the proposed scheme to be promising for single-shot pump–probe spectroscopy in a wide range of spectroscopic applications.

Magnetically tuned continuous transition from weak to strong coupling in terahertz magnon polaritons

Andrey Baydin, Kenji Hayashida, Takuma Makihara, Fuyang Tay, Xiaoxuan Ma, Wei Ren, Guohong Ma, G. T … Show more authors

Physical Review Research 5 ( 1 ) L012039 2023.3 [Reviewed]

DOI Web of Science

Language：English Publishing type：Research paper (scientific journal) Joint Work

Other Link： https://journals.aps.org/prresearch/abstract/10.1103/PhysRevResearch.5.L012039

Investigation of ultrafast excited-state dynamics at the nanoscale with terahertz field-induced electron tunneling and photon emission

Ikufumi Katayama, Kensuke Kimura, Hiroshi Imada, Yousoo Kim, and Jun Takeda

Journal of Applied Physics 133 ( 11 ) 10903 2023.3 [Reviewed] [Invited]

DOI Web of Science CiNii Research

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：American Institute of Physics Single Work

The combination of terahertz (THz) pulses with scanning tunneling microscopy (STM) enables us to investigate ultrafast dynamics at material surfaces with high spatial (nanoscale) and temporal (femtosecond) resolution. In this Perspective, we review the basic principles of THz-STM, outline the related literature, and discuss its future outlook capable of advancing nanoscience, especially by introducing further combination of THz-STM with scanning tunneling luminescence spectroscopy, which can extract more fruitful information about nanoscale materials via obtaining luminescence spectra compared to just observing the net tunneling current induced by THz pulses in THz-STM. By shining THz pulses onto an STM tip, we can observe plasmon luminescence locally confined between the tip and the surface, whose spectrum changes with tip conditions. The combined approach is a stepping stone toward investigating the ultrafast excited-state dynamics of nanoscale materials with high spatiotemporal resolution.

Other Link： https://aip.scitation.org/doi/10.1063/5.0144218

Pulse-to-pulse Ultrafast Dynamics of Highly Photoexcited Ge2Sb2Te5 Thin Films

62 ( 2 ) 022001 2023.2 [Reviewed]

DOI Web of Science CiNii Research

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Single Work

Other Link： https://iopscience.iop.org/article/10.35848/1347-4065/acb476

Single-Shot Terahertz Waveform Detection by Chirped-Pulse Up-Conversion Spectroscopy with Dispersion Compensation

Tamaki, R; Takeda, J; Katayama, I

2023 48TH INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER, AND TERAHERTZ WAVES, IRMMW-THZ 2023

DOI Web of Science

Language：Japanese Publishing type：Research paper (scientific journal) Joint Work

Exciton formation in a single molecule triggered by field-driven ultrafast electron tunneling

Kimura Kensuke, Imada Hiroshi, Katayama Ikufumi, Takeda Jun, Kim Yousoo

日本表面真空学会学術講演会要旨集 2023 ( 0 ) 2Bp02 2023

DOI CiNii Research

Language：English Publishing type：Research paper (scientific journal) Publisher：公益社団法人日本表面真空学会 Joint Work

The combination of a single-cycle THz pulse and a scanning tunneling microscope (STM) enables to investigate ultrafast dynamics with the nanometer and picosecond resolutions [1-5]. In THz-STM, the tunnel barrier of STM junction is modulated by the oscillation of electric field of THz pulse. Due to the bandwidth of electrical circuit, conventional THz-STM only measures “time-averaged” or “net” field-driven tunneling current, thus it is difficult to determine how electrons are manipulated by positive and negative components within a single-cycle electric field oscillation. By combining a photon detection system with a THz-STM, it enables to investigate excitation and energy dissipation processes triggered by THz-field-driven tunneling [5]. In this work, we revealed field-driven ultrafast charge transfer between the STM tip and a molecule by measuring luminescence signal from the molecule (Fig. 1a).Single-cycle THz pulses were generated by using optical rectification of laser pulses from a Yb fiber laser (1035 nm, 50 MHz, 40 W) in a LiNbO3 prism. The carrier envelope phase (CEP) of THz pulse can be tuned by using a CEP shifter [4]. The CEP-controlled THz pulses were guided to an STM (5 K, 1 × 10-11 Torr) and focused to the junction. The CEP of near field THz electric field was evaluated by measuring the tunneling current on a clean Ag(111) surface (Fig. 1a) [4]. The photons generated at the STM tip is collected using a lens inside the STM and directed out of the ultrahigh vacuum chamber, where it was refocused onto a grating spectrometer with a charge coupled device (CCD) photon detector.Figure 1b shows THz-STM luminescence (THz-STL) spectra of a Pd-phthalocyanine (PdPc) on NaCl ultrathin film grown on Ag(111). The luminescence peak originated from the fluorescence of a PdPc is observed at 1.84 eV only when THz pulses were irradiated (red spectra in Fig. 1b). Figure 1c shows CEP dependence of molecular luminescence intensity, where CEP = π is defined as ΔCEP = 0. In the CEP dependence, the luminescence intensity is maximum at around ΔCEP = π/6 and zero at around ΔCEP = ± π. This result indicates that the THz waveform is responsible for the exciton formation. In this presentation, we would like to discuss the mechanism of exciton formation in a molecule by THz-field-driven ultrafast charge transfer between the STM tip and the molecule.[1] T. L. Cocker et al., Nature 539, 263 (2016).[2] K. Yoshioka et al., Nat. Photon. 10, 762 (2016).[3] S. Yoshida et al., ACS photon. 8 315 (2021).[4] K. Yoshioka et al., Nano Lett. 18, 5198 (2019)[5] K. Kimura et al., ACS photon. 8, 982 (2021).

K-point longitudinal acoustic phonons are responsible for ultrafast intervalley scattering in monolayer MoSe2

Soungmin Bae, Kana Matsumoto, Hannes Raebiger, Ken-ichi Shudo, Yong-Hoon Kim, Ørjan Sele Handegård, … Show more authors

Nature Communications 13 4279 2022.7 [Reviewed]

DOI

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Joint Work

Other Link： https://www.nature.com/articles/s41467-022-32008-6

Pulse-to-pulse detection of terahertz radiation emitted from the femtosecond laser ablation process

Tamaki Ryo, Kasai Tatsuki, Asai Gaku, Hata Daiki, Kubo Hajime, Takigawa Yuichi, Takeda Jun, Katayam … Show more authors

OPTICS EXPRESS 30 ( 13 ) 23622 - 23630 2022.6 [Reviewed]

DOI Web of Science PubMed CiNii Research

Language：English Publishing type：Research paper (scientific journal) Publisher：Optica Joint Work

Determining the dynamics of electrons and ions emitted from a target material during laser ablation is crucial for desirable control of laser processing. However, these dynamics are still challenging to understand because of a lack of ubiquitous spectroscopic tools to observe tangled-up dynamics appearing at ultrafast timescales. Here by harnessing highly sensitive single-shot terahertz time-domain spectroscopy using an echelon mirror, we investigate pulse-to-pulse temporal profile of terahertz radiation generated from the material surface. We clearly found that the carrier–envelope phase and the electric field amplitude of the terahertz waveform systematically vary between the pre- and post-ablation depending on the laser fluence and irradiated pulse numbers. Our results provide a stepping-stone towards perception of Coulomb explosion occurring throughout the laser ablation process, which is indispensable for future laser processing applications.

Magnetic Control of Soft Chiral Phonons in PbTe

Andrey Baydin, Felix G. G. Hernandez, Martin Rodriguez-Vega, Anderson K. Okazaki, Fuyang Tay, G. Ti … Show more authors

Physical Review Letters 128 ( 7 ) 075901 2022.2 [Reviewed]

DOI Web of Science PubMed CiNii Research

Language：English Publishing type：Research paper (scientific journal) Publisher：American Physical Society Joint Work

PbTe crystals have a soft transverse optical phonon mode in the terahertz frequency range, which is known to efficiently decay into heat-carrying acoustic phonons, resulting in anomalously low thermal conductivity. Here, we studied this phonon via polarization-dependent terahertz spectroscopy. We observed softening of this mode with decreasing temperature, indicative of incipient ferroelectricity, which we explain through a model including strong anharmonicity with a quartic displacement term. In magnetic fields up to 25 T, the phonon mode splits into two modes with opposite handedness, exhibiting circular dichroism. Their frequencies display Zeeman splitting together with an overall diamagnetic shift with increasing magnetic field. Using a group-theoretical approach, we demonstrate that these observations are the result of magnetic field-induced morphic changes in the crystal symmetries through the Lorentz force exerted on the lattice ions. Thus, our Letter reveals a novel process of controlling phonon properties in a soft ionic lattice by a strong magnetic field.

Femtosecond Ablation Dynamics Observed with Terahertz Radiation

Tamaki Ryo, Kasai Tatsuki, Asai Gaku, Hata Daiki, Kubo Hajime, Takigawa Yuichi, Takeda Jun, Katayam … Show more authors

2022 47TH INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER AND TERAHERTZ WAVES (IRMMW-THZ 2022) 2022

DOI Web of Science

Language：Japanese Publishing type：Research paper (scientific journal) Joint Work

Fano resonance of optical phonons in a multilayer graphene stack

Kitajima Masahiro, Katayama Ikufumi, Handegard Orjan Sele, Nagao Tadaaki, Chiashi Shohei, Maruyama … Show more authors

JAPANESE JOURNAL OF APPLIED PHYSICS 60 ( 12 ) 122006 2021.12 [Reviewed]

DOI Web of Science CiNii Research

Language：English Publishing type：Research paper (scientific journal) Publisher：{IOP} Publishing Joint Work

We studied Fano interference between the Raman spectrum of G-band phonons and electron continuum in a multilayer graphene stack. The thickness and power dependencies of the Fano interference coefficient ∣1/q∣ in the G-mode, where q is the Fano asymmetry parameter, were spatially visualized and analyzed using the Gaussian-convoluted Breit–Wigner–Fano function. The estimated ∣1/q∣ decreases with an increase in the layer number and laser power in the low-power region at least for monolayer, bilayer, and trilayer graphene. In the higher-power region, ∣1/q∣ increases with power only for monolayer graphene. The observed behaviors of ∣1/q∣ reflect the phase difference of Raman signals from the electron continuum and G-band and possibly originate from changes in the electronic relaxation time and the Fermi level of graphene owing to the laser heating of the sample.

Observation of ultrafast amorphization dynamics in GeCu2Te3 thin films using echelon-based single-shot transient absorbance spectroscopy

Yusuke Arashida, Takayuki Suzuki, Shuhei Nara, Ikufumi Katayama, Yasuo Minami, Satoshi Shindo, Yuji … Show more authors

Applied Physics Letters 119 ( 6 ) 061102-1 - 061102-4 2021.8 [Reviewed]

DOI Web of Science

Language：English Publishing type：Research paper (scientific journal) Joint Work

Ultrastrong magnon–magnon coupling dominated by antiresonant interactions

Takuma Makihara, Kenji Hayashida, G. Timothy Noe II, Xinwei Li, Nicolas Marquez Peraca, Xiaoxuan Ma … Show more authors

Nature Communications 12 ( 1 ) 3115-1 - 3115-9 2021.5 [Reviewed]

DOI Web of Science PubMed

Language：English Publishing type：Research paper (scientific journal) Joint Work

High-throughput terahertz spectral line imaging using an echelon mirror

Gaku Asai, Daiki Hata, Shintaro Harada, Tatsuki Kasai, Yusuke Arashida, Ikufumi Katayama

Optics Express 29 ( 3 ) 3515 - 3523 2021.2 [Reviewed]

DOI Web of Science PubMed

Language：English Publishing type：Research paper (scientific journal) Publisher：The Optical Society Joint Work

Waveform sampling on an atomic scale

Jun Takeda, Ikufumi Katayama

Nature Photonics 15 ( 2 ) 70 - 71 2021.1 [Reviewed]

DOI Web of Science

Language：English Publishing type：Research paper (scientific journal) Joint Work

Terahertz-Field-Driven Scanning Tunneling Luminescence Spectroscopy

Kensuke Kimura, Yuta Morinaga, Hiroshi Imada, Ikufumi Katayama, Kanta Asakawa, Katsumasa Yoshioka, … Show more authors

ACS Photonics 8 ( 4 ) A - F 2021.1 [Reviewed]

DOI Web of Science

Language：English Publishing type：Research paper (scientific journal) Joint Work

Observation of STM-luminescence induced by THz-field-driven tunneling electrons

Kimura Kensuke, Morinaga Yuta, Imada Hiroshi, Katayama Ikufumi, Asakawa Kanta, Yoshioka Katsumasa, … Show more authors

Abstract book of Annual Meeting of the Japan Society of Vacuum and Surface Science 2021 ( 0 ) 2Cp05R 2021

DOI CiNii Research

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：The Japan Society of Vacuum and Surface Science Joint Work

In this work, we developed a novel nano-spectroscopy technique, entitled terahertz-field-driven scanning tunneling luminescence (THz-STL) spectroscopy, based on a scanning tunneling microscope (STM). THz-STL spectroscopy combines two cutting-edge STM techniques, THz-STM and STL spectroscopy, and enables to investigate atomic-scale energy dissipations triggered by a THz single-cycle pulse. We introduced single-cycle THz pulses into an STM junction (Au tip and Ag(111)) and measured visible photons generated by THz-field-driven electrons. By utilizing this technique, we detected the radiative decay of a localized plasmon excited by THz-field-driven electrons and clarified mechanistic differences in plasmon excitation between field- and DC-driven electrons.

High-Repetition-Rate Single-Shot Ultrafast Spectroscopy Using Time-Stretching Method

KOBAYASHI Masataka, TAKEDA Jun, KATAYAMA Ikufumi

The Review of Laser Engineering 49 ( 4 ) 212 2021 [Reviewed] [Invited]

DOI CiNii Research

Authorship：Last author,　Corresponding author Language：Japanese Publishing type：Research paper (scientific journal) Publisher：The Laser Society of Japan Joint Work

Nanoscale phase change on Ge2Sb2Te5 thin films induced by optical near fields with photoassisted scanning tunneling microscope

Kanta Asakawa, Dang-il Kim, Shotaro Yaguchi, Mikito Tsujii, Katsumasa Yoshioka, Keisuke Kaneshima, … Show more authors

Applied Physics Letters 117 ( 21 ) 1102-1 - 1102-5 2020.11 [Reviewed]

DOI Web of Science CiNii Research

Language：English Publishing type：Research paper (scientific journal) Publisher：American Institute of Physics Joint Work

A scanning probe microscope coupled with either femtosecond laser pulses or terahertz pulses holds great promise not only for observing ultrafast phenomena but also for fabricating desirable structures at the nanoscale. In this study, we demonstrate that a few-nanometer-scale phase change can be non-thermally stored on the Ge2Sb2Te5 surface by a laser-driven scanning tunneling microscope (STM). An atomically flat Ge2Sb2Te5 surface was irradiated with the optical near-field generated by introducing femtosecond laser pulses to the STM tip-sample junction. The STM topographic images showed that few-nanometer-scale mounds appeared after irradiation. In addition, tunneling conductance spectra showed that the bandgap increased by 0.2 eV in the area of 5 × 5 nm2. These indicate that the nanoscale crystal-to-amorphous phase change was induced by the STM-tip-induced near field. Our approach presented here offers an unprecedented increase in the recording density of optical storage devices and is, therefore, expected to facilitate the development of next-generation information technology.

Observation of Photoinduced Terahertz Gain in GaAs Quantum Wells: Evidence for Radiative Two-Exciton-to-Biexciton Scattering

Li Xinwei, Yoshioka Katsumasa, Zhang Qi, Peraca Nicolas Marquez, Katsutani Fumiya, Gao Weilu, Noe G … Show more authors

PHYSICAL REVIEW LETTERS 125 ( 16 ) 2020.10 [Reviewed]

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Language：Japanese Publishing type：Research paper (scientific journal) Joint Work

Other Link： https://doi.org/10.1103/PhysRevLett.125.167401

Supercontinuum spectral phase interferometry with isolated attosecond pulse

Oshima Akihiro, Mashiko Hiroki, Chen Ming-Chang, Katayama Ikufumi, Takeda Jun, Oguri Katsuya

JSAP Annual Meetings Extended Abstracts 2020.2 ( 0 ) 667 - 667 2020.8

DOI CiNii Research

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：The Japan Society of Applied Physics Joint Work

Spatially resolved spectral phase interferometry with an isolated attosecond pulse

Hiroki Mashiko, Ming-Chang Chen, Koji Asaga, Akihiro Oshima, Ikufumi Katayama, Jun Takeda, Tadashi … Show more authors

Optics Express 28 ( 14 ) 21025 - 21034 2020.7 [Reviewed]

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Language：English Publishing type：Research paper (scientific journal) Joint Work

Ultrafast optical modulation of Dirac electrons in gated single-layer graphene

Katayama Ikufumi, Inoue Kei-ichi, Arashida Yusuke, Wu Yang, Yang Hyunsoo, Inoue Taiki, Chiashi Shoh … Show more authors

PHYSICAL REVIEW B 101 ( 24 ) 245408 2020.6 [Reviewed]

DOI Web of Science CiNii Research

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：American Physical Society ({APS}) Joint Work

Fermi level dependence of ultrafast optical responses of single-layer graphene has been investigated using sub-10-fs pump-probe spectroscopy under bias voltages. We observe the ultrafast thermalization of photoexcited carriers, whose dynamics can be modulated via bias-induced change of the Fermi level. The relaxation time and the amplitude of the electronic response are maximized when the Fermi level reaches approximately half of the excitation photon energy. From the analysis of the pump-pulse-induced optical conductivity change, we find that the bias-induced blocking of the relaxation pathways and the pump-induced change of the electronic temperature and the Fermi level significantly contribute to the observed ultrafast optical modulation. The results demonstrate the controllability of the ultrafast optical responses in single-layer graphene, which could be useful for future ultrafast electro-optic graphene devices.

Other Link： https://doi.org/10.1103/PhysRevB.101.245408

Macroscopic Ionic Flow in a Superionic Conductor Na+ beta-Alumina Driven by Single-Cycle Terahertz Pulses

Minami Yasuo, Ofori-Okai Benjamin, Sivarajah Prasahnt, Katayama Ikufumi, Takeda Jun, Nelson Keith A … Show more authors

PHYSICAL REVIEW LETTERS 124 ( 14 ) 2020.4 [Reviewed]

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Language：Japanese Publishing type：Research paper (scientific journal) Publisher：American Physical Society ({APS}) Joint Work

Other Link： https://doi.org/10.1103/PhysRevLett.124.147401

シングルショット時間領域分光

武田　淳、小林真隆、片山郁文

光学 49 423 - 428 2020 [Reviewed]

Language：Japanese Publishing type：Research paper (scientific journal) Joint Work

Observation of Ultrastrong Magnon-Magnon Coupling in YFeO3 Using Terahertz Magnetospectroscopy

Makihara Takuma, Noe G. Timothy II, Li Xinwei, Hayashida Kenji, Peraca Nicolas Marquez, Tian Kevin, … Show more authors

2020 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) 2020

Web of Science

Language：Japanese Publishing type：Research paper (scientific journal) Joint Work

Subcycle mid-infrared coherent transients at 4 MHz repetition rate applicable to light-wave-driven scanning tunneling microscopy

Katsumasa Yoshioka, Ippo Igarashi, Shoji Yoshida, Yusuke Arashida, Ikufumi Katayama, Jun Takeda, an … Show more authors

Optics Letters 44 ( 21 ) 5350 - 5353 2019.11 [Reviewed]

DOI

Language：English Publishing type：Research paper (scientific journal) Joint Work

Terahertz field-induced phenomena in Dirac electron systems

55 ( 54 ) 589 - 599 2019.11 [Reviewed]

Language：Japanese Publishing type：Research paper (scientific journal) Joint Work

Other Link： https://iss.ndl.go.jp/books/R100000002-I000000008643-00

Selective Reduction Mechanism of Graphene Oxide Driven by the Photon Mode versus the Thermal Mode

Masaki Hada, Kiyoshi Miyata, Satoshi Ohmura, Yusuke Arashida, Kohei Ichiyanagi, Ikufumi Katayama, T … Show more authors

ACS Nano 2019 Vol.13 ( 9 ) 10103 - 10112 2019.8 [Reviewed]

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Language：English Publishing type：Research paper (scientific journal) Publisher：ACS Publications Joint Work

Dielectric cross-shapedresonator-based metasurface for vortex beam generation at mid-IR and THz wavelengths

Raghu Dharmavarapu, Ken-ichi Izumi, Ikufumi Katayama, Soon Hock Ng, Jitraporn Vongsvivut, Mark J. T … Show more authors

Nanophotonics Vol.8 ( 7 ) 1263 - 1270 2019.7 [Reviewed]

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Language：English Publishing type：Research paper (scientific journal) Joint Work

Other Link： https://doi.org/10.1515/nanoph-2019-0112

An echelon-based single shot optical and terahertz Kerr effect spectrometer

Griffin Mead, Ikufumi Katayama, Jun Takeda, Geoffrey A. Blake

Review of Scientific Instruments Vol.90 ( 5 ) 2019.5 [Reviewed]

DOI

Language：English Publishing type：Research paper (scientific journal) Publisher：AIP Joint Work

Other Link： https://doi.org/10.1063/1.5088377

Multi-timescale pump-probe spectroscopy using time-encoding and time-stretching methods

Ikufumi Katayama,Masataka Kobayashi,J. Johnson

SPIE.DIGITAL LIBRARY 2019.3 [Reviewed]

DOI

Language：English Publishing type：Research paper (scientific journal) Joint Work

Fast-frame single-shot pump-probe spectroscopy with chirped-fiber Bragg gratings

Masataka Kobayashi, Yusuke Arashida, Genki Yamashita, Eiichi Matsubara, Masaaki Ashida, Jeremy A. J … Show more authors

Optics Letters 44 ( 1 ) 163 - 166 2019 [Reviewed]

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Language：English Publishing type：Research paper (scientific journal) Joint Work

High precision frequency measurement of terahertz waves using optical combs from a Mach–Zehnder-modulator-based flat comb generator

Isao Morohashi, Ikufumi Katayama, Mayu Kirigaya, Yoshihisa Irimajiri, Norihiko Sekine, and Iwao Hos … Show more authors

Optics Letters 44 ( 3 ) 487 - 490 2019 [Reviewed]

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Language：English Publishing type：Research paper (scientific journal) Joint Work

Terahertz Faraday and Kerr Rotation Spectroscopy of Bi1-xSbx Films in High Magnetic Fields up to 30 Tesla

X. Li, K. Yoshioka, M. Xie, T. Hagiwara, G. T. Noe II, W. Lee, N. Marquez Peraca, W. Gao, T. Hagiwa … Show more authors

Physical Review B 100 ( 11 ) 115145：1 - 15 2019 [Reviewed]

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Language：English Publishing type：Research paper (scientific journal) Joint Work

Ultrafast carrier generation in Bi1-xSbx thin films induced by intense monocycle terahertz pulses

Katayama Ikufumi, Kawakami Hiroki, Araki Kotaro, Arashida Yusuke, Minami Yasuo, Nien Lie-Wei, Hande … Show more authors

XXI INTERNATIONAL CONFERENCE ON ULTRAFAST PHENOMENA 2018 (UP 2018) 205 2019

DOI Web of Science

Language：Japanese Publishing type：Research paper (scientific journal) Joint Work

Electric dipole oscillation in solids characterized by Fourier transform extreme ultraviolet attosecond spectroscopy

Chisuga Yuta, Mashiko Hiroki, Oguri Katsuya, Katayama Ikufumi, Takeda Jun, Gotoh Hideki

XXI INTERNATIONAL CONFERENCE ON ULTRAFAST PHENOMENA 2018 (UP 2018) 205 2019

DOI Web of Science

Language：Japanese Publishing type：Research paper (scientific journal) Joint Work

Sub-cycle Manipulation of Electrons in a Tunnel Junction with Phase-controlled Single-cycle THz Near-fields

Yoshioka Katsumasa, Katayama Ikufumi, Arashida Yusuke, Ban Atsuhiko, Kawada Yoichi, Takahashi Hiron … Show more authors

XXI INTERNATIONAL CONFERENCE ON ULTRAFAST PHENOMENA 2018 (UP 2018) 205 2019

DOI Web of Science

Language：Japanese Publishing type：Research paper (scientific journal) Joint Work

Terahertz-field-induced carrier generation in Bi1−xSbx Dirac electron systems

I. Katayama,H. Kawakami,T. Hagiwara,Y. Arashida,Y. Minami,L.-W. Nien,O. S. Handegard,T. Nagao,M. Ki … Show more authors

PHYSICAL REVIEW B 98 ( 21 ) 214302-1 - 214302-5 2018.12 [Reviewed]

DOI

Language：English Publishing type：Research paper (scientific journal) Joint Work

Ultrafast optical control of multiple coherent phonons in silicon carbide using a pulse-shaping technique

Yusuke Arashida, Kyosuke Murakami, Ikufumi Katayama and Jun Takeda

Applied Physics Express 11 ( 12 ) 122701-1 - 122701-4 2018.10 [Reviewed]

DOI

Language：English Publishing type：Research paper (scientific journal) Single Work

Nonlinear terahertz dynamics of Dirac electrons in Bi thin films

Ikufumi Katayama,Yasuo Minami,Yusuke Arashida,Orjan S. Handegard,Tadaaki Nagao,Masahiro Kitajima,Ju … Show more authors

Proceedings 10756 2018.9 [Reviewed]

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Language：English Publishing type：Research paper (scientific journal) Joint Work

Long-lived photoinduced response observed under extreme photoexcitation densities in a one-dimensional Peierls insulator

Johanna W. Wolfson, Samuel W. Teitelbaum, Taeho Shin, Ikufumi Katayama, Taro Kawano, Jun Takeda, an … Show more authors

Phys. Rev. B 98 ( 5 ) 2018.8 [Reviewed]

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Language：English Publishing type：Research paper (scientific journal) Joint Work

Tailoring Single-Cycle Near Field in a Tunnel Junction with Carrier-Envelope Phase-Controlled Terahertz Electric Fields

Yoshioka Katsumasa,Katayama Ikufumi,Arashida Yusuke,Ban Atsuhiko,Kawada Yoichi,Konishi Kuniaki,Taka … Show more authors

Nano Lett 18 ( 8 ) 5198 - 5204 2018.6 [Reviewed]

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Language：English Publishing type：Research paper (scientific journal) Joint Work

Bias-induced modulation of ultrafast carrier dynamics in metallic single-walled carbon nanotubes

Keisuke Maekawa, Kazuhiro Yanagi, Yasuo Minami, Masahiro Kitajima1,Ikufumi Katayama, Jun Takeda,

Phys. Rev. B 97 ( 7 ) 2018.2 [Reviewed]

DOI

Language：English Publishing type：Research paper (scientific journal) Publisher：APS Physics Joint Work

Nanoscale electron manipulation in metals with intense THz electric fields

Jun Takeda, Katsumasa Yoshioka, Yasuo Minami and Ikufumi Katayama

Journal of Physics D: Applied Physics 51 ( 10 ) 2018.2 [Reviewed]

DOI

Language：English Publishing type：Research paper (scientific journal) Publisher：IOP Publishing Single Work

Multi-petahertz electron interference in Cr:Al2O3 solid-state material

Hiroki Mashiko,Yuta Chisuga,Ikufumi Katayama,Katsuya Oguri,Hiroyuki Masuda,Jun Takeda,Hideki Gotoh

Nature Communications 9 ( 1468 ) 2018 [Reviewed]

DOI

Language：English Publishing type：Research paper (scientific journal) Joint Work

Anharmonic phonon-polariton dynamics in ferroelectric LiNbO3 studied with single-shot pump-probe imaging spectroscopy

T.Kuribayashi,T.Motoyama,Y.Arashida,I.Katayama,J.Takeda

Journal of Applied Physics 123 ( 17 ) 2018 [Reviewed]

DOI

Language：English Publishing type：Research paper (scientific journal) Joint Work

Simultaneous acquisition of complex transmittance and birefringence with two counter-rotating, circularly polarized THz pulses

Yoichi Kawada, Katsumasa Yoshioka, Yusuke Arashida, Ikufumi Katayama, Jun Takeda, and Hironori Taka … Show more authors

Optics Express 26 ( 23 ) 30420 - 30434 2018 [Reviewed]

DOI

Language：English Publishing type：Research paper (scientific journal) Joint Work

Sub-cycle Control of Electrons in a Tunnel Junction with THz Near-fields

Yoshioka Katsumasa, Ban Atsuhiko, Katayama Ikufumi, Arashida Yusuke, Kawada Yoichi, Takahashi Hiron … Show more authors

Meeting Abstracts of the Physical Society of Japan 73 ( 0 ) 1492 - 1492 2018 [Reviewed]

DOI

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：The Physical Society of Japan Joint Work

Other Link： https://ci.nii.ac.jp/naid/130007646534

Vacuum Bloch?Siegert shift in Landau polaritons with ultra-high cooperativity

X. Li, M.Bamba, Q. Zhang, S. Fallahi, G. C. Gardner, W. Gao, M. Lou, K. Yoshioka, M. J. Manfra, and … Show more authors

Nat. Photon. 12 324-329 - 329 2018 [Reviewed]

Language：English Publishing type：Research paper (scientific journal) Joint Work

Simultaneous Acquisition of Complex Transmittance and Birefringence with Two Counter-Rotating Circularly Polarized THz Pules,

Y. Kawada, K. Yoshioka, Y. Arashida, I. Katayama, J. Takeda, and H. Takahash

Opt. Exp. 26 030420 - 030434 2018 [Reviewed]

DOI

Language：English Publishing type：Research paper (scientific journal) Joint Work

高強度テラヘルツ波によるナノ空間電子制御

武田　淳、片山郁文、吉岡克将

固体物理 52 439 - 446 2017 [Reviewed]

Language：Japanese Publishing type：Research paper (scientific journal) Joint Work

Single-Shot Terahertz Time-Domain Spectroscopy in Pulsed High Magnetic Fields

G. T. Noe, I. Katayama, F. Katsutani, J. J. Allred, J. A. Horowitz, D. M. Sullivan, Q. Zhang, F. Se … Show more authors

Optics Express 24 ( 26 ) 30328 2016.12 [Reviewed]

DOI

Language：English Publishing type：Research paper (scientific journal) Publisher：OSA Joint Work

Other Link： https://www.osapublishing.org/oe/home.cfm

Real-Space Coherent Manipulation of Electrons in a Single Tunnel Junction by Single-Cycle Terahertz Electric Fields

K. Yoshioka, I. Katayama, Y. Minami, and J. Takeda

Nature Photonics 10 ( 12 ) 762 - 765 2016.12 [Reviewed]

DOI Web of Science

Language：English Publishing type：Research paper (scientific journal) Publisher：NATURE PUBLISHING GROUP Joint Work

Other Link： http://www.nature.com/nphoton/index.html

High-Acquisition-Rate Single-Shot Pump-Probe Measurements Using Time-Stretching Method

M. Kobayashi, Y. Minami, C. L. Johnson, P. D. Salmans, N. R. Ellsworth, J. Takeda, J. A. Johnson, a … Show more authors

Scientific Reports 6 37614;1 - 6 2016.11 [Reviewed]

DOI Web of Science

Language：English Publishing type：Research paper (scientific journal) Publisher：NATURE PUBLISHING GROUP Joint Work

Other Link： http://www.nature.com/srep/

Single-Shot Terahertz Time-Domain Spectroscopy in Pulsed High Magnetic Fields

G. T. Noe, I. Katayama, F. Katsutani, J. J. Allred, J. A. Horowitz, D. M. Sullivan, Q. Zhang, F. Se … Show more authors

Opt. Exp. 24 30326 - 30337 2016 [Reviewed]

Language：English Publishing type：Research paper (scientific journal) Joint Work

Terahertz-Induced Acceleration of Massive Dirac Electrons in Semimetal Bismuth

Y. Minami, K. Araki, T. D. Dao, T. Nagao, M. Kitajima, J. Takeda, and I. Katayama

Scientific Reports 5 15870;1 - 6 2015.11 [Reviewed]

DOI Web of Science

Language：English Publishing type：Research paper (scientific journal) Publisher：NATURE PUBLISHING GROUP Joint Work

Terahertz-Induced Acceleration of Massive Dirac Electrons in Semimetal Bismuth

Terahertz Dielectric Response of Photoexcited Carriers in Si Revealed via Single-Shot Optical-Pump and Terahertz-Probe Spectroscopy

Y. Minami, K. Horiuchi, K. Masuda, J. Takeda, and I. Katayama

Applied Physics Letters 107 ( 17 ) 171104;1 - 4 2015.10 [Reviewed]

DOI Web of Science

Language：English Publishing type：Research paper (scientific journal) Publisher：AIP Joint Work

We have demonstrated accurate observations of terahertz (THz) dielectric response due to photoexcited carriers in a Si plate via single-shot optical-pump and THz-probe spectroscopy. In contrast to conventional THz time-domain spectroscopy, this spectroscopic technique allows single-shot detection of the THz response of materials at a given delay time between the pump and THz pulses, thereby sufficiently extending the time interval between the pump pulses. As a result, we can accurately measure the dielectric properties of materials, while avoiding artifacts in the response caused by the accumulation of long-lived photoexcited carriers. Using our single-shot scheme, the transmittance of a Si plate was measured in the range of 0.5-2.5 THz with different pump fluences. Based on a Drude model analysis, the optically induced complex dielectric constant, plasma frequency, and damping rate in the THz region were quantitatively evaluated. (C) 2015 AIP Publishing LLC.

Other Link： http://aip.scitation.org/journal/apl

ナノカーボンのディラック電子＝フォノン間相互作用ダイナミクス

片山郁文、武田淳、北島正弘

日本物理学会誌 70 770 - 775 2015.10 [Reviewed]

Language：Japanese Publishing type：Research paper (scientific journal) Joint Work

サブ10 fsの超短パルスレーザーを用いた超高速分光法によるMass-less Dirac電子系の電子格子相互作用を明らかにした研究を紹介した論文

Ultrafast Time-Resolved Electron Diffraction Revealing the Nonthermal Dynamics of Near-UV Photoexcitation-Induced Amorphization in Ge2Sb2Te5

M. Hada, W. Oba, M. Kuwahara, I. Katayama, T. Saiki, J. Takeda, and K. G. Nakamura

Scientific Reports 5 13530;1 - 9 2015.8 [Reviewed]

DOI Web of Science

Language：English Publishing type：Research paper (scientific journal) Publisher：NATURE PUBLISHING GROUP Joint Work

Because of their robust switching capability, chalcogenide glass materials have been used for a wide range of applications, including optical storages devices. These phase transitions are achieved by laser irradiation via thermal processes. Recent studies have suggested the potential of nonthermal phase transitions in the chalcogenide glass material Ge2Sb2Te5 triggered by ultrashort optical pulses; however, a detailed understanding of the amorphization and damage mechanisms governed by nonthermal processes is still lacking. Here we performed ultrafast time-resolved electron diffraction and single-shot optical pump-probe measurements followed by femtosecond near-ultraviolet pulse irradiation to study the structural dynamics of polycrystalline Ge2Sb2Te5. The experimental results present a nonthermal crystal-to-amorphous phase transition of Ge2Sb2Te5 initiated by the displacements of Ge atoms. Above the fluence threshold, we found that the permanent amorphization caused by multi-displacement effects is accompanied by a partial hexagonal crystallization.

Other Link： http://www.nature.com/srep/

Real-Time Observation of Phonon-Polariton Dynamics in Ferroelectric LiNbO3 in Time-Frequency Space

Y. Ikegaya, H. Sakaibara, Y. Minami, I. Katayama and J. Takeda

Applied Physics Letters 107 ( 6 ) 062901;1 - 5 2015.8 [Reviewed]

DOI Web of Science

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER INST PHYSICS Joint Work

We demonstrate the real-time observation of phonon-polariton propagation in ferroelectric LiNbO3 using a single-shot spectroscopic setup that employs an echelon mirror. The echelon mirror provides a spatially encoded time delay for the probe pulse; therefore, the ultrafast transient behavior of materials can be detected on a single-shot basis. Using optical Kerr gate apparatus, forward and backward propagating E-mode phonon-polaritons were simultaneously induced via an impulsive stimulated Raman scattering process, and subsequently, their dynamics were readily mapped in time-frequency space using heterodyne detection. The two phonon-polaritons appeared on opposite sides of the central probe wavelength and were symmetrically imaged against the ordinary and extraordinary probe lights. By taking into account coupling of the lowest E-mode phonon-polariton to a low-frequency relaxational mode, not only the phonon-polariton dispersion but also the wavevector dependence of the damping rate was unveiled and quantitatively evaluated. (C) 2015 AIP Publishing LLC.

Other Link： http://aip.scitation.org/journal/apl

反射型エシェロンを用いた時間・周波数2次元イメージング分光

武田淳，南康夫，片山郁文

レーザー研究 43 208 - 212 2015.4 [Reviewed]

Language：Japanese Publishing type：Research paper (scientific journal) Joint Work

反射型エシェロンを用いて時間周波数イメージングを行う技術について解説した。

Terahertz-field-induced Nonlinear Electron Delocalization in Au Nanostructures

Katsumasa Yoshioka, Yasuo Minami, Ken-ichi Shudo, Thang D. Dao, Tadaaki Nagao, Masahiro Kitajima, J … Show more authors

Nano Letters 15 ( 2 ) 1036 - 1040 2015.2 [Reviewed]

DOI Web of Science

Language：English Publishing type：Research paper (scientific journal) Publisher：American Chemical Society Joint Work

Other Link： http://pubs.acs.org/journal/nalefd

Ultrafast Time-Resolved Electron Diffraction Revealing the Nonthermal Dynamics of Near-UV Photoexcitation-Induced Amorphization in Ge2Sb2Te5

M. Hada, W. Oba, M. Kuwahara, I. Katayama, T. Saiki, J. Takeda, and K. G. Nakamura

Sci. Rep. 5 ( 1530 ) 1 - 9 2015

Language：English Publishing type：Research paper (scientific journal) Joint Work

Terahertz Dielectric Response of Photoexcited Carriers in Si Revealed via Single-Shot Optical-Pump and Terahertz-Probe Spectroscopy

Y. Minami, K. Horiuchi, K. Masuda, J. Takeda, and I. Katayama

Appl. Phys. Lett. 107 ( 171104 ) 1 - 4 2015 [Reviewed]

Language：English Publishing type：Research paper (scientific journal) Joint Work

Terahertz-Induced Acceleration of Massive Dirac Electrons in Semimetal Bismuth

Y. Minami, K. Araki, T. D. Dao, T. Nagao, M. Kitajima, J. Takeda, and I. Katayama

Sci. Rep. 5 ( 15870 ) 1 - 6 2015 [Reviewed]

Language：English Publishing type：Research paper (scientific journal) Joint Work

Real-Time Observation of Phonon-Polariton Dynamics in Ferroelectric LiNbO3 in Time-Frequency Space

Y. Ikegaya, H. Sakaibara, Y. Minami, I. Katayama and J. Takeda

Appl. Phys. Lett 107 ( 062901 ) 1 - 5 2015 [Reviewed]

Language：English Publishing type：Research paper (scientific journal) Joint Work

Terahertz-field-induced Nonlinear Electron Delocalization in Au Nanostructures

K. Yoshioka, Y. Minami, K. Shudo, T. D. Dao, T. Nagao, M. Kitajima, J. Takeda, and I. Katayama,

Nano Letters 15 1036 - 1040 2015 [Reviewed]

DOI

Language：English Publishing type：Research paper (scientific journal) Joint Work

Time-Frequency Two-Dimensional Imaging Spectroscopy Using a Reflective Echelon Mirror

J. Takeda, Y. Minami, and I. Katayama,

Rev. Laser Eng 43 208 - 212 2015 [Reviewed]

Language：English Publishing type：Research paper (scientific journal) Joint Work

Resonance enhancement of first- and second-order coherent phonons in metallic single-walled carbon nanotubes

K. Sato, K. Tahara, Y. Minami, I. Katayama, M. Kitajima, H. Kawai, K. Yanagi, and J. Takeda

Physical Review B 90 ( 23 ) 235435: 1 - 5 2014.12 [Reviewed]

DOI Web of Science

Language：English Publishing type：Research paper (scientific journal) Publisher：American Physical Society Joint Work

Other Link： http://journals.aps.org/prb/

Nonlinear electron dynamics of gold ultrathin films induced by intense terahertz waves

Yasuo Minami, Jun Takeda, Thang Duy Dao, Tadaaki Nagao, Masahiro Kitajima, and Ikufumi Katayama

Applied Physics Letters 105 ( 24 ) 241107: 1 - 4 2014.12 [Reviewed]

DOI Web of Science

Language：English Publishing type：Research paper (scientific journal) Publisher：American Institute of Physics Joint Work

Other Link： http://scitation.aip.org/content/aip/journal/apl

テラヘルツ時間領域分光法による薄膜・表面の物性評価

片山郁文、南康夫、武田淳

表面科学 35 ( 12 ) 680 - 685 2014.12 [Reviewed] [Invited]

DOI

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：表面科学会 Joint Work

テラヘルツ時間領域分光法を用いた、線形非線形の分光結果に関する解説を行った。フォノン、キャリア、超伝導ギャップの非線形性を議論した。

Other Link： https://www.jstage.jst.go.jp/browse/jsssj/35/12/_contents/-char/ja/

Ultrafast crystalline-to-amorphous phase transition in Ge2Sb2Te5 chalcogenide alloy thin film using single-shot imaging spectroscopy

Jun Takeda, Wataru Oba, Yasuo Minami, Toshiharu Saiki, and Ikufumi Katayama

Applied Physics Letters 104 ( 26 ) 261903: 1 - 4 2014.6 [Reviewed]

DOI Web of Science

Language：English Publishing type：Research paper (scientific journal) Publisher：American Institute of Physics Joint Work

Other Link： http://scitation.aip.org/content/aip/journal/apl

Ultra-broadband IR and THz generation and detection with ultrashort pulses

Masaaki Ashida, Eiichi Matsubara, and Ikufumi Katayama

Proceedings of SPIE 8964 896409: 1 - 15 2014.2 [Reviewed] [Invited]

DOI

Language：English Publishing type：Research paper (scientific journal) Joint Work

<KATAYAMA Ikufumi>

Papers - KATAYAMA Ikufumi